Subway workers in Busan and Daegu are back at work, ending a one-day strike after labor and management reached an agreement on wage hikes. But subway workers in the western port of Incheon are still on strike.

In Ulsan, unionized workers at Hyundai Motor laid down their tools in response to a call by the Korean Confederation of Trade Unions for a four-hour walkout, seeking improved working conditions and the scrapping of a law establishing special economic zones. Hyundai Motor's union said it would strike for two to four hours every day beginning Wednesday.

The union is demanding an eleven percent wage hike, a 40-hour workweek and increased bonuses.

Meanwhile, business leaders have accused unions of holding the national economy hostage to push their demands, and threatened to cut investment or to move plants overseas.